var htmlSize = document.documentElement.clientWidth||document.body.clientWidth;
var dom = document.getElementsByTagName("html")[0];
dom.style.fontSize=htmlSize/120+"px";
window.addEventListener("resize",function(e){
	var htmlSize = document.documentElement.clientWidth||document.body.clientWidth;
	document.getElementsByTagName("html")[0];
	dom.style.fontSize=htmlSize/120+"px";
});